General bacterial porin family. General bacterial porins are a family of proteins from the outer membranes of Gram-negative bacteria. The porins act as molecular filters for hydrophilic compounds. They are responsible for the 'molecular sieve' properties of the outer membrane. Porins form large water-filled channels which allow the diffusion of hydrophilic molecules into the periplasmic space. Some porins form general diffusion channels that allow any solute up to a certain size to cross the membrane, while other porins are sp
Cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein and chloride channel in vertebrates that is encoded by the CFTR gene. CFTR is an ABC transporter-class ion channel that codes for a protein that conducts chloride and thiocyanate ions across epithelial cell membranes.
The CFTR gene provides instructions for making a protein called the cystic fibrosis transmembrane conductance regulator. This protein functions as a channel across the membrane of cells that produce mucus, sweat, saliva, tears, and digestive enzymes.ome affected males have a mild mutation in one copy of the CFTR gene in each cell and a more severe, cystic fibrosis-causing mutation in the other copy of the gene. Mutations in the CFTR gene disrupt the function of the chloride channel, preventing the usual flow of chloride ions and water into and out of cells.